HPE FlexNetwork 5510 HI Series, Руководство по настройке Mpls

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Figure 16 Label acceptance control diagram
A label advertisement policy on an LSR and a label acceptance policy on its upstream LSR can
achieve the same purpose. To reduce network load, use the label advertisement policy as a best
practice.
You must create an IP prefix list before you configure a label acceptance policy. For information
about IP prefix list configuration, see
Layer 3—IP Routing Configuration Guide .
To configure a label acceptance policy:
Step Command Remarks
1. Enter system view.
system-view N/A
2. Enter LDP view or enter
LDP-VPN instance
view.
•
Enter LDP view:
mpls ldp
•
Enter LDP-VPN instance view:
a. mpls ldp
b. vpn-instance
vpn-instance-name
N/A
3. Configure a label
acceptance policy.
accept-label peer peer-lsr-id prefix-list
prefix-list-name
By default, LDP accepts all label
mappings.
Configuring LDP loop detection
LDP detects and terminates LSP loops in the following ways:
•
Maximum hop count —LDP adds a hop count in a label request or label mapping message.
The hop count value increments by 1 on each LSR. When the maximum hop count is reached,
LDP considers that a loop has occurred and terminates the establishment of the LSP.
•
Path vector —LDP adds LSR ID information in a label request or label mapping message. Each
LSR checks whether its LSR ID is contained in the message. If it is not, the LSR adds its own
LSR ID into the message. If it is, the LSR considers that a loop has occurred and terminates
LSP establishment. In addition, when the number of LSR IDs in the message reaches the path
vector limit, LDP also considers that a loop has occurred and terminates LSP establishment.
To configure LDP loop detection:
Step Command Remarks
1. Enter system view.
system-view N/A
Label mappings permitted
by the IP prefix list
LSR A
LSR B
Accept the
label mappings
Drop the label
mappings
Label mappings not permitted
by the IP prefix list
LSR C
Do not filter label
mappings